1. Field of the Invention
This present invention relates to a personal computer and, more particularly, to an apparatus for sensing system bus clock speed and processor power supply voltage within a personal computer motherboard to which a microprocessor is delegated for connection.
2. Description of the Related Art
A personal computer is generally know to comprise, at a minimum, an execution unit, memory and various input/output ports. The execution unit is often referred to as a microprocessor, and the microprocessor is typically linked to the memory via a system bus. The system bus, sometimes referred to as a local bus, links address and data information sent between the microprocessor and memory. The system bus can also link the microprocessor, or memory, to various other subsystems, some of which are arranged on a single printed circuit board. The singular printed circuit board is often referred to as a motherboard.
A typical motherboard housed within a personal computer comprises one or more layers of printed conductors extending at least partially across the motherboard. The printed conductors surface at localized regions of the motherboard. Those regions allow connection of integrated or discreet devices using various connection techniques, such as plug-and-socket, wire wrap, or solder.
A substantial percentage of motherboards manufactured today can be reconfigured. Specifically, modern motherboards come equipped with numerous switches or jumpers which can alter the operation of one or more subsystems arranged thereon. For example, the clocking speed of the system bus can be modified by connecting a jumper across two pins extending from the motherboard. The power supply voltage supplied to a microprocessor can also be changed, for example, by connecting a jumper or actuating a switch. It is therefore necessary when modifying signals within printed conductors of a motherboard that the operator know which jumper to connect or which switch to activate.
Typical motherboards have numerous switches and jumpers, wherein the particular switch and jumper of interest must be identified in order to reconfigure, e.g., the system bus frequency or the processor supply voltage. Generally speaking, a motherboard is manufactured so that it can accommodate dissimilar microprocessors, or microprocessors which respond to differing system bus frequencies or power supply voltages. When assembling a personal computer, it would be desirable to quickly identify the particular jumper or switch of interest so that operation of the motherboard can be made compatible with the desired microprocessor. Once the settings are located, the motherboard can readily be altered to match the specification of a microprocessor which will thereafter be coupled to the motherboard. A mechanism for quickly identifying the jumpers or switches of interest is therefore desired so as not to damage a microprocessor subsequently linked to the motherboard.